OBJECTIVE: Despite availability of an array of antihypertensive drugs, malignant hypertension remains a life-threatening condition, and new therapeutic strategies for the treatment of malignant hypertension and malignant hypertension-associated organ damage are needed. The aim of the present study was to assess the effects of nitric oxide (NO)-independent soluble guanylyl cyclase (sGC) stimulator on the course of malignant hypertension. The second aim was to investigate if the treatment with sodium-glucose cotransporter type 2 (SGLT2) inhibitor would augment the expected beneficial actions of the sGC stimulation on the course of malignant hypertension. METHODS: As a model of malignant hypertension, Ren-2 transgenic rats (TGR) treated with nonspecific NO synthase inhibitor (Nω-nitro- l -arginine methyl ester, l -NAME) was used. Blood pressure (BP) was monitored by radiotelemetry, and the treatment was started 3 days before administration of l -NAME. RESULTS: The treatment with sGC stimulator BAY 41-8543, alone or combined with SGLT2 inhibitor empagliflozin, abolished malignant hypertension-related mortality in TGR receiving l -NAME. These two treatment regimens also prevented BP increases after l -NAME administration in TGR, and even decreased BP below values observed in control TGR, and prevented cardiac dysfunction and malignant hypertension-related morbidity. The treatment with the SGLT2 inhibitor empagliflozin did not further augment the beneficial actions of sGC stimulator on the course of malignant hypertension-related mortality. CONCLUSION: The treatment with NO-independent sGC stimulator displayed marked protective actions on the course of malignant hypertension-related mortality and malignant hypertension-related cardiac damage. This suggests that application of sGC stimulator could be a promising therapeutic means for the treatment of malignant hypertension.

• Klíčová slova
• malignant hypertension, renin–angiotensin system, sodium-glucose cotransporter type 2 inhibitor, soluble guanylyl cyclase stimulator,
• MeSH
• benzhydrylové sloučeniny farmakologie   MeSH
• glifloziny MeSH
• glukosidy farmakologie   terapeutické užití   MeSH
• hypertenze maligní * prevence a kontrola   farmakoterapie   MeSH
• krevní tlak účinky léků   MeSH
• krysa rodu Rattus MeSH
• NG-nitroargininmethylester farmakologie   MeSH
• potkani transgenní MeSH
• pyrazoly * farmakologie   terapeutické užití   MeSH
• pyrimidiny * terapeutické užití   farmakologie   MeSH
• rozpustná guanylátcyklasa * metabolismus   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• BAY 41-8543 MeSH Prohlížeč
• benzhydrylové sloučeniny MeSH
• empagliflozin MeSH Prohlížeč
• glifloziny MeSH
• glukosidy MeSH
• morfoliny MeSH
• NG-nitroargininmethylester MeSH
• pyrazoly * MeSH
• pyrimidiny * MeSH
• rozpustná guanylátcyklasa * MeSH

Heart failure (HF) is a leading cause of morbidity and mortality, often driven by prolonged exposure to pathological stimuli such as pressure and volume overload. These factors contribute to excessive oxidative stress, adverse cardiac remodeling, and dysregulation of the nitric oxide-soluble guanylate cyclase-cyclic guanosine monophosphate (NO-sGC-cGMP) signaling pathway. Given the urgent need for effective treatments, this study investigated the potential of sGC stimulators to mitigate HF progression. We utilized male hypertensive Ren-2 transgenic (TGR) rats and a volume-overload HF model induced by an aortocaval fistula (ACF). Rats received the sGC stimulator BAY 41-8543 (3 mg/kg/day) for 30 weeks, while normotensive Hannover Sprague-Dawley rats served as controls. At the study endpoint (40 weeks of age), left ventricular tissue was analyzed using mass spectrometry, Western blotting, and histological assessment. TGR rats treated with sGC stimulators exhibited a significant increase in key antioxidant proteins (SOD1, CH10, ACSF2, NDUS1, DHE3, GSTM2, and PCCA), suggesting enhanced resistance to oxidative stress. However, sGC stimulator treatment also upregulated extracellular matrix remodeling markers (MMP-2, TGF-β, and SMAD2/3), which are typically associated with fibrosis. Despite this, Masson's trichrome staining revealed reduced collagen deposition in both TGR and TGR-ACF rats receiving sGC stimulators. Notably, all untreated TGR-ACF rats succumbed before the study endpoint, preventing direct assessment of sGC stimulator effects in advanced HF. These findings highlight the therapeutic potential of sGC stimulators in HF, particularly through their antioxidant effects. However, their concurrent influence on fibrosis warrants further investigation to optimize treatment strategies.

• Klíčová slova
• heart failure with reduced ejection fraction, reactive oxygen/nitrogen species, renin‐angiotensin system, soluble guanylate cyclase stimulator,
• MeSH
• agonisté guanylátcyklasy * farmakologie   terapeutické užití   MeSH
• krysa rodu Rattus MeSH
• modely nemocí na zvířatech MeSH
• oxidační stres účinky léků   MeSH
• potkani Sprague-Dawley MeSH
• potkani transgenní MeSH
• pyrazoly * farmakologie   terapeutické užití   MeSH
• pyrimidiny * farmakologie   terapeutické užití   MeSH
• remodelace komor účinky léků   MeSH
• rozpustná guanylátcyklasa * metabolismus   MeSH
• srdeční selhání * farmakoterapie   etiologie   patofyziologie   metabolismus   patologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• agonisté guanylátcyklasy * MeSH
• BAY 41-8543 MeSH Prohlížeč
• morfoliny MeSH
• pyrazoly * MeSH
• pyrimidiny * MeSH
• rozpustná guanylátcyklasa * MeSH

The aim of the present study was to assess systemic circulatory and tissue activities of both the classical arm and of the alternative arm of the renin-angiotensin system (RAS) in a new transgenic rat line (TG7371) that expresses angiotensin-(1-7) (ANG 1-7)-producing fusion protein; the results were compared with the activities measured in control transgene-negative Hannover Sprague-Dawley (HanSD) rats. Plasma and tissue concentrations of angiotensin II (ANG II) and ANG 1-7, and kidney mRNA expressions of receptors responsible for biological actions of ANG II and ANG 1-7 [i.e. ANG II type 1 and type 2 (AT1 and AT2) and Mas receptors] were assessed in TG7371 transgene-positive and in HanSD rats. We found that male TG7371 transgene-positive rats exhibited significantly elevated plasma, kidney, heart and lung ANG 1-7 concentrations as compared with control male HanSD rats; by contrast, there was no significant difference in ANG II concentrations and no significant differences in mRNA expression of AT1, AT2 and Mas receptors. In addition, we found that in male TG7371 transgene-positive rats blood pressure was lower than in male HanSD rats. These data indicate that the balance between the classical arm and the alternative arm of the RAS was in male TGR7371 transgene-positive rats markedly shifted in favor of the latter. In conclusion, TG7371 transgene-positive rats represent a new powerful tool to study the long-term role of the alternative arm of the RAS in the pathophysiology and potentially in the treatment of cardio-renal diseases.

• Klíčová slova
• Angiotensin II, Angiotensin-(1-7), Renin-angiotensin system, TG7371 transgenic rat,
• MeSH
• angiotensin I * metabolismus   MeSH
• angiotensin II * MeSH
• kardiovaskulární nemoci metabolismus   genetika   MeSH
• krevní tlak fyziologie   MeSH
• krysa rodu Rattus MeSH
• ledviny metabolismus   MeSH
• nemoci ledvin metabolismus   genetika   MeSH
• peptidové fragmenty * metabolismus   MeSH
• potkani Sprague-Dawley * MeSH
• potkani transgenní * MeSH
• protoonkogen Mas MeSH
• receptor angiotensinu typ 1 genetika   metabolismus   MeSH
• receptory spřažené s G-proteiny genetika   metabolismus   MeSH
• rekombinantní fúzní proteiny metabolismus   MeSH
• renin-angiotensin systém * fyziologie   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiotensin I (1-7) MeSH Prohlížeč
• angiotensin I * MeSH
• angiotensin II * MeSH
• peptidové fragmenty * MeSH
• protoonkogen Mas MeSH
• receptor angiotensinu typ 1 MeSH
• receptory spřažené s G-proteiny MeSH
• rekombinantní fúzní proteiny MeSH

Combination of chronic kidney disease (CKD) and heart failure (HF) results in extremely high morbidity and mortality. The current guideline-directed medical therapy is rarely effective and new therapeutic approaches are urgently needed. The study was designed to examine if renal denervation (RDN) will exhibit long-standing beneficial effects on the HF- and CKD-related morbidity and mortality. Fawn-hooded hypertensive rats (FHH) served as a genetic model of CKD and fawn-hooded low-pressure rats (FHL) without CKD served as controls. HF was induced by creation of aorto-caval fistula (ACF). RDN was performed 28 days after creation of ACF and the follow-up period was 70 days. ACF FHH subjected to sham-RDN had survival rate of 34 % i.e. significantly lower than 79 % observed in sham-denervated ACF FHL. RDN did not improve the condition and the final survival rate, both in ACF FHL and in ACF FHH. In FHH basal albuminuria was markedly higher than in FHL, and further increased throughout the study. RDN did not lower albuminuria and did not reduce renal glomerular damage in FHH. In these rats creation of ACF resulted in marked bilateral cardiac hypertrophy and alterations of cardiac connexin-43, however, RDN did not modify any of the cardiac parameters. Our present results further support the notion that kidney damage aggravates the HF-related morbidity and mortality. Moreover, it is clear that in the ACF FHH model of combined CKD and HF, RDN does not exhibit any important renoprotective or cardioprotective effects and does not reduce mortality. Key words Chronic kidney disease, Heart failure, Renal denervation, Fawn-hooded hypertensive rats.

• MeSH
• denervace metody   MeSH
• hypertenze * patofyziologie   komplikace   MeSH
• kardiorenální syndrom * patofyziologie   chirurgie   etiologie   MeSH
• krysa rodu Rattus MeSH
• ledviny * inervace   MeSH
• modely nemocí na zvířatech MeSH
• sympatektomie * metody   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

All anthracyclines, including doxorubicin (DOXO), the most common and still indispensable drug, exhibit cardiotoxicity with inherent risk of irreversible cardiomyopathy leading to heart failure with reduced ejection fraction (HFrEF). Current pharmacological strategies are clearly less effective for this type of HFrEF, hence an urgent need for new therapeutic approaches. The prerequisite for success is thorough understanding of pathophysiology of this HFrEF form, which requires an appropriate animal model of the disease. The aim of this study was to comprehensively characterise a novel model of HF with cardiorenal syndrome, i.e. DOXO-induced HFrEF with nephrotic syndrome, in which DOXO was administered to Ren-2 transgenic rats (TGR) via five intravenous injections in a cumulative dose of 10 mg/kg of body weight (BW). Our analysis included survival, echocardiography, as well as histological examination of the heart and kidneys, blood pressure, but also a broad spectrum of biomarkers to evaluate cardiac remodelling, fibrosis, apoptosis, oxidative stress and more. We have shown that the new model adequately mimics the cardiac remodelling described as "eccentric chamber atrophy" and myocardial damage typical for DOXO-related cardiotoxicity, without major damage of the peritoneum, lungs and liver. This pattern corresponds well to a clinical situation of cancer patients receiving anthracyclines, where HF develops with some delay after the anticancer therapy. Therefore, this study may serve as a comprehensive reference for all types of research on DOXO-related cardiotoxicity, proving especially useful in the search for new therapeutic strategies.

• Klíčová slova
• Chemotherapy induced heart failure, Doxorubicin, Experimental model of heart failure, NO/sGC/cGMP pathway, Ren-2 transgenic hypertensive rat,
• MeSH
• doxorubicin * škodlivé účinky   MeSH
• krysa rodu Rattus MeSH
• ledviny účinky léků   patofyziologie   MeSH
• modely nemocí na zvířatech * MeSH
• nefrotický syndrom * chemicky indukované   farmakoterapie   patofyziologie   MeSH
• oxidační stres účinky léků   MeSH
• potkani transgenní * MeSH
• protinádorová antibiotika škodlivé účinky   MeSH
• srdeční selhání * chemicky indukované   patofyziologie   MeSH
• tepový objem * účinky léků   MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• mužské pohlaví MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• doxorubicin * MeSH
• protinádorová antibiotika MeSH

The aim was to evaluate the effects of renal denervation (RDN) on autoregulation of renal hemodynamics and the pressure-natriuresis relationship in Ren-2 transgenic rats (TGR) with aorto-caval fistula (ACF)-induced heart failure (HF). RDN was performed one week after creation of ACF or sham-operation. Animals were prepared for evaluation of autoregulatory capacity of renal blood flow (RBF) and glomerular filtration rate (GFR), and of the pressure-natriuresis characteristics after stepwise changes in renal arterial pressure (RAP) induced by aortic clamping. Their basal values of blood pressure and renal function were significantly lower than with innervated sham-operated TGR (p < 0.05 in all cases): mean arterial pressure (MAP) (115 ± 2 vs. 160 ± 3 mmHg), RBF (6.91 ± 0.33 vs. 10.87 ± 0.38 ml.min-1.g-1), urine flow (UF) (11.3 ± 1.79 vs. 43.17 ± 3.24 µl.min-1.g-1) and absolute sodium excretion (UNaV) (1.08 ± 0.27 vs, 6.38 ± 0.76 µmol.min-1.g-1). After denervation ACF TGR showed improved autoregulation of RBF: at lowest RAP level (80 mmHg) the value was higher than in innervated ACF TGR (6.92 ± 0.26 vs. 4.54 ± 0.22 ml.min-1.g-1, p < 0.05). Also, the pressure-natriuresis relationship was markedly improved after RDN: at the RAP of 80 mmHg UF equaled 4.31 ± 0.99 vs. 0.26 ± 0.09 µl.min-1.g-1 recorded in innervated ACF TGR, UNaV was 0.31 ± 0.05 vs. 0.04 ± 0.01 µmol min-1.g-1 (p < 0.05 in all cases). In conclusion, in our model of hypertensive rat with ACF-induced HF, RDN improved autoregulatory capacity of RBF and the pressure-natriuresis relationship when measured at the stage of HF decompensation.

• Klíčová slova
• Ren-2 transgenic hypertensive rat, Renal autoregulation, Renal blood flow, Volume-overload heart failure, sodium excretion,
• MeSH
• hodnoty glomerulární filtrace MeSH
• hypertenze * MeSH
• kardiorenální syndrom * MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• ledviny MeSH
• natriuréza MeSH
• píštěle * MeSH
• potkani transgenní MeSH
• renální oběh MeSH
• srdeční selhání * MeSH
• sympatektomie MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH

The aim of the present study was to assess the autoregulatory capacity of renal blood flow (RBF) and of the pressure-natriuresis characteristics in the early phase of heart failure (HF) in rats, normotensive and with angiotensin II (ANG II)-dependent hypertension. Ren-2 transgenic rats (TGR) were employed as a model of ANG II-dependent hypertension. HF was induced by creating the aorto-caval fistula (ACF). One week after ACF creation or sham-operation, the animals were prepared for studies evaluating in vivo RBF autoregulatory capacity and the pressure-natriuresis characteristics after stepwise changes in renal arterial pressure (RAP) induced by aortic clamping. In ACF TGR the basal mean arterial pressure, RBF, urine flow (UF), and absolute sodium excretion (UNaV) were all significantly lower tha n in sham-operated TGR. In the latter, reductions in renal arterial pressure (RAP) significantly decreased RBF whereas in ACF TGR they did not change. Stepwise reductions in RAP resulted in marked decreases in UF and UNaV in sham-operated as well as in ACF TGR, however, these decreases were significantly greater in the former. Our data show that compared with sham-operated TGR, ACF TGR displayed well-maintained RBF autoregulatory capacity and improved slope of the pressure-natriuresis relationship. Thus, even though in the very early HF stage renal dysfunction was demonstrable, in the HF model of ANG II-dependent hypertensive rat such dysfunction and the subsequent HF decompensation cannot be simply ascribed to impaired renal autoregulation and pressure-natriuresis relationship.

• Klíčová slova
• Ren-2 transgenic hypertensive rat, Renal autoregulation, Renal blood flow, Sodium excretion, Volume-overload heart failure,
• MeSH
• angiotensin II farmakologie   MeSH
• homeostáza MeSH
• hypertenze * MeSH
• krevní tlak MeSH
• krysa rodu Rattus MeSH
• ledviny MeSH
• natriuréza MeSH
• potkani transgenní MeSH
• renální oběh MeSH
• sodík MeSH
• srdeční selhání * MeSH
• zvířata MeSH
• Check Tag
• krysa rodu Rattus MeSH
• zvířata MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• angiotensin II MeSH
• sodík MeSH